13021728 has 96 divisors (see below), whose sum is σ = 37013760. Its totient is φ = 3993600.

The previous prime is 13021727. The next prime is 13021741. The reversal of 13021728 is 82712031.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 13021698 and 13021707.

It is not an unprimeable number, because it can be changed into a prime (13021721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 128878 + ... + 128978.

It is an arithmetic number, because the mean of its divisors is an integer number (385560).

Almost surely, 2^13021728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13021728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18506880).

13021728 is an abundant number, since it is smaller than the sum of its proper divisors (23992032).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13021728 is a wasteful number, since it uses less digits than its factorization.

13021728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210 (or 202 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 13021728 is about 3608.5631489556. The cubic root of 13021728 is about 235.2643953437.

Adding to 13021728 its reverse (82712031), we get a palindrome (95733759).

The spelling of 13021728 in words is "thirteen million, twenty-one thousand, seven hundred twenty-eight".